A process of this kind is known from published EP-A 0 204 032. This process determines that a disk is partly compressed in its circumferential area, the circumferential area is then split, the split area is expanded and compressed again, if required, and subsequently provided with a profile. For the manufacture of asymmetric pulleys, provision is made for the compressed circumferential area to be split off-center such that the resulting two collars have different wall thicknesses.
A disadvantage of this known process resides in that, during manufacture, the asymmetric splitting poses problems due to uneven forces occurring at the disk. Due to these uneven forces, the collars of the circumferential area of the disk resulting from the splitting may easily exhibit irregular structural properties and, hence, irregular strength properties. This is disadvantageous to the continued processing and to the service life of the finished product.